The present invention relates to pen plotters and, in particular, to a method and apparatus for simplifying the display and inputting of menu selection information. More specifically, it relates to simplified menu display and entry apparatus for changing the current operating parameter values in a pen plotter having random access memory (RAM) containing changeable current operating parameter values, a plotting mechanism, plotter logic for controlling the plotting mechanism, and a set of pen control buttons associated with up, down, left, and right movement of a pen of the pen plotter, wherein the apparatus comprises, alpha-numeric display means for displaying alpha-numeric characters to a user; a sensible ON LINE function button; a sensible MENU function button; menu function select mode logic means for sensing the ON LINE function button and the MENU function button, for placing the pen plotter in a menu selection mode when the MENU function button is pressed while the pen plotter is in a plotter control mode, and for placing the pen plotter in the plotter control mode when the ON LINE function button is pressed while the pen plotter is in the menu selection mode; read only memory (ROM) means containing menu definition means for defining a plurality of top-to-bottom and left-to-right alpha-numeric menu definitions to be displayed on the alpha-numeric display means to a user, the menu definitions being associated with respective ones of a plurality of functions and subfunctions of the pen plotter and operating parameters associated therewith, the menu definitions being in a two-dimensional form wherein top level menu definitions associated with major functions and parameters of the plotter are in one dimension while sub-functions portions of a top level menu definition is a second dimension of a menu definition matrix; and, menu input logic means for sensing the pen control buttons, for starting at top level ones of the plurality of menu definitions and displaying next and previous ones in order in response to sensing the pressing of up and down ones of the pen control buttons respectively, for starting at beginning ones of sub-function menu definition portions of selected ones of the plurality of menu definitions and displaying next and previous ones in order in response to sensing the pressing of right and left ones of the pen control buttons respectively, and for entering a parameter value associated with a displayed one of the plurality of menu definitions into the RAM containing the changeable current operating parameter values when the menu function select mode logic means is in the menu selection mode.
Pen plotters are popular peripheral devices for use with CAD systems and the like for providing graphics output, particularly at larger drawings sizes. They provide the advantage of professional quality drawings at a price which is much lower than other forms of graphics output devices.
Like most peripheral devices attached to computer (and some other contemporary stand-alone electronics devices like facsimile machines, etc.), pen plotters provide a user with the ability to set various operating parameters associated with the device from the device itself. Early devices sometimes accomplished this with so-called DIP switches that could be set, and some devices still employ DIP switches for some or all of their parameter setting functions. While DIP switches are adequate for setting things like BAUD rate in a modem or between pulse and tone dialing in a facsimile machine, and the like, which seldom if ever change, there are functions associated with some devices which may need to be changed more regularly to suit the needs of different users or of different projects employing the device.
In a device having an alpha-numeric display 10 as in FIG. 1, there is usually a set of menu/function buttons 12 associated with the display 10 which can be employed to perform menu and function selection through the display. The analog DIP switches in some cases have even been replaced with so-called "soft" switches which can be changed through the display 10 and buttons 12. The drawing of FIG. 1, however, is typical of the control panel 14 of a prior art pen plotter and, therefore, there are also pen direction control buttons 16 included with the panel 14. A functional block diagram for a prior art pen plotter 18 thus configured is shown in FIG. 2. The plotter 18 includes plotter logic 20 connected to control a plotting mechanism 22. The plotter logic 20, in turn, is connected to random access memory (RAM) 24, read only memory (ROM) 25, display 10, menu buttons 12, and the pen buttons 16.
A conventional configuration as in FIGS. 1 and 2 offers several disadvantages to a pen plotter offering many features and, therefore, many menu options. The cost of adding menu buttons 12 adds to the cost of the plotter. More important, however, the user has to remember how to use the various buttons 12 or refer to an operator's manual in order to find out. The result is that, like a vast number of modern devices offering many wonderful features from VCRs to CD players, the average high technology pen plotter user is either not interested in learning how to implement the functions or simply cannot figure out the process and, therefore, many of the features go unused. This phenomenon of modern electronics is characterized by the number of VCRs that are seen simply flashing 12:00 on the time display because their users can't or can't be bothered to program them.
Wherefore, it is the object of this invention to provide a method and apparatus for simplifying the display and inputting of menu selection information in a modern high technology pen plotter offering its users a large number of menu selections, options, and functions from which to choose.
Other objects and benefits of the invention will become apparent from the detailed description which follows hereinafter when taken in conjunction with the drawing figures which accompany it.